Field of the Invention
The present invention concerns a method for producing a valve for regulating a fluid, the valve including a valve housing with a central part and with two connection ends, the connection ends extending away from the central part, wherein there is arranged a valve body internally of the central part, for example, with a through-going aperture, arranged in a valve seat and connected to a valve spindle, the valve spindle arranged in a spindle guide stub on the valve housing, wherein the valve housing is at least partly constituted by a plastically deformed item, and wherein the method of producing the valve housing with spindle guide stub at least includes the following steps:                providing a tubular item;        providing a cutout with an internal edge on the tubular item;        providing a plastic deformation in the form of a collar through the cutout, whereby a spindle guide stub is formed.        
The invention further concerns a valve for regulating a fluid, the valve including a valve housing with a central part and with two connection ends, the connection ends extending away from the central part, wherein internally of the central part there is arranged a valve body, for example, with a through-going aperture, wherein the valve body is arranged in a valve seat and connected to a valve spindle, the valve spindle arranged in a spindle guide stub on the valve housing, wherein the valve housing is made from a plastically deformed tubular item and includes a collared spindle guide stub.
Description of Related Art
It is commonly known to make valves, e.g., ball valves, and thereby valve housings of several parts and then assemble these parts around a valve seat and a valve body. Such valves are typically made of brass or other copper-based alloy and are typically assembled by corresponding screw threads in respective parts, or alternatively, by means of bolts.
When speaking of a ball valve, the valve body is, as indicated by the name, spherical and with an outer size which is greater than the connecting openings in the valve housing. Such a valve therefore has a valve housing with a geometry in which valve seat and valve body are disposed. The valve housing is typically joined in the vicinity of the valve body as the latter require the largest internal dimension. Such valves are typically made of cast items which are shaped by machining to the desired geometry. This shaping process is, however, rather cost-intensive for several reasons. The individual work pieces are to be cast, handled and machined one by one in a metal cutting unit. Since the work pieces are individually machined, the process is time-consuming, irrespective of the application of modern and rapid processes.
In addition to the handling and machining of the cast work pieces prior to assembling around a valve seat and a valve body, the cost of the material also plays a significant role. Brass or other suitable alloys are expensive and imply an appreciably greater cost than e.g., common weldable carbon steel.
Thus, there is an expressed desire for making valves for heating and cooling systems, for potable water and for other purposes in steel, e.g., carbon steel or stainless steel which is cheaper and which can be worked with modern production equipment directly from a plate piece or a tube piece faster and cheaper than possible when casting and machining work pieces of brass.
At the same time, it is greatly desired to entirely avoid performing welding processes on a valve as such processes cause the work pieces to be set up at least one more time and that a welding process is to be performed, which of course raises the cost of the product.
U.S. Pat. No. 4,546,790 discloses a valve for regulating a fluid in which the valve housing itself includes a central part and two connection ends which extend away from the central part. Internally of the central part there is arranged a valve body in a valve seat, the valve body connected to a valve spindle. The valve spindle is arranged in a spindle guide stub collared on the valve housing. According to U.S. Pat. No. 4,546,790, a spindle guide stub is collared, but there is no indication that the end of the spindle guide stub achieves its final shape after collaring and thus is not to be worked or machined any more, something which quite common. Besides, the spindle guide stub indicated in U.S. Pat. No. 4,546,790 has the drawback that it neither has any kind of contact faces that may serve as stop for the movement of the operating handle nor includes means that lock or retain the valve spindle in axial direction. The absence of a contact face acting as a stop is less important in some cases as by certain types of valves it can be felt whether the valve body is in open or closed position. By ball valves, however, it is impossible to feel the position as in principle they can be rotated indefinitely. Therefore, it is necessary to integrate a kind of contact face on the valve such that the position of the valve body in the valve housing can be known with certainty. By the solution according to U.S. Pat. No. 4,546,790, it is only possible to determine the movement of the valve body in that after formation of a plastically deformed spindle guide stub, such a contact face/stop is retrofitted, typically provided by welding or some kind of machining. Also, some kind of securing of the valve spindle in axial direction is to be provided. These process steps are unwanted because of e.g., the action of heat and not the least the costs associated with respective handling and machining processes.
U.S. Pat. No. 6,916,011 B2 discloses a ball valve comprising a body having at a central position a seat-producing part formed with a stem-inserting hole with a cutout having an edge with a shape such that the edge on the cutout after collaring faces inward and towards the central part of the valve housing. The cutout which faces inwardly towards the central part of the valve housing necessitates a larger valve housing and the risk of damaging O-rings when assembling the stem from inside the valve.